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Romy the Cat wrote:

Got today a party of the 6C18C from 1960s, an interesting tube. The plate looks like 1/4 times larger and has no bridge between the halves. The 6C18C has even less plate impedance than 6C33C and it appears that it futures inside more “colorful” metal then the 6C33C. I have no idea how it sounds at this point and I wonder in which channel I should stick it is. The lower plate impedance and the larger anode would suggest that it should be a LF channel. The year of the production suggests that it should be HF channel. (The newer Russian tubes are the more vulgar they sound for whatever reasons). I would be an interesting try…

The damn Russkis saved on everything. It was not enough for them that they manufactured vacuumed tubes (from the same batch!!!) that have 4db different in gain but they also managed to manufacture the same tubes "gradually improving the efficiency of production"… namely removing the anode material for sake of damn economy. I'm sure they samed a lotQ  The last time I have experiences it in Russians when I inspected Lamm M1.1 amplifiers and detected that the heatsinks design employed paralleled output transistors  but there was actually no paralleled transistors installed in the slots. “It works well without them”, Vladimir Lamm assured me. At then time I did not know any better answer….

Anyhow, inspecting and playing with different years of the 6C18C and 6C33C and observing how their plates dissipate heat I detected an interesting fact: Vladimir Lamm had good teachers and somewhere in the mid 60s Russians started to “save” on the plate’s volume. I wonder how much they saved? Ima sure Lamm did saved $2.5 for his MOSFER over the cost of the $19.000.00 amplifier....

The picture above presents 3 tubes, from left to right. First tube is 6C18C production of 1963, 1964 and 1965 (they all look identically). The second tube is 6C18C production of 1968, 1969. The third is 6C33C production of 70s and 80s. Now is a request for a wild guess: even if to presume that the plate materials are the same then which anode would dissipate more power?

The caT

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